GoldenGate Introduction and Classic Architecture Components

 

GoldenGate Introduction:

Oracle GoldenGate is a software product that allows you to replicate, filter, and transform data from one database to another database.

Using Oracle GoldenGate, you can move committed transactions across heterogeneous database.

Why Do You Need Oracle GoldenGate?

To effectively move data from one system to another system in real-time with zero-downtime. Oracle GoldenGate is the Oracle’s solution to replicate and integrate data.

The key features are:

• Data movement in real-time, by reducing latency.
•  Only committed transactions are moved, so that the data is consistent and performance will improve.
•  Can replicate the data from an Oracle database to a different heterogeneous database.
•  Continuous extraction and replication of transactional DML and DDL operations to keep source and target data consistent.
•  Simple architecture and easy configuration

GoldenGate Architecture:

There are different architecture that can be configured, that is from simple uni-directional architecture to the more complex peer-to-peer configuration. Whatever be the architecture, the GoldenGate makes the administration easier.

Classic and Microservices architecture:

GoldenGate supports two architecture, the Classic architecture and Microservices Architecture (MA).

Classic Architecture	Microservices Architecture
This provides processes and files required to effectively move data across a variety of topologies.	This provides REST enabled service as part of Oracle GoldenGate environment. The REST-enabled services provide remote configuration, administration, and monitoring through webpages, command line and APIs.

Components of Oracle GoldenGate Classic Architecture:

 

 Manager:

 Manager is the control process of Oracle GoldenGate.  It must be running on each system in the Oracle GoldenGate configuration before the Extract or Replicat processes can be started.

One Manager process can control many Extract or Replicat processes.

Functions of Manager process are:

(i)  Starts the GoldenGate processes

(ii)  Purges trace files based on retention rules

(iii)  Creates event, error or threshold reports

Extract:

              Extract or Capture process, will capture the committed transaction from the redologs.

Can configure Extract process for the following use case:

1.    Initial Load:

            Before GoldenGate configuration, if there is a data in the source objects and to transfer that we go for Initial Load.  i.e, Extract process captures the static data directly from the source objects and transfers it to the target database. 

Initial data is a data migration which is performed only once.

            2.  Change Synchronization:

When you set up the GoldenGate to keep the source data synchronized with the target data.  The Extract process captures the DML and DDL operations performed on the configured objects after the Initial Load.

Extract process writes all the captured committed data into a trail file on the Source database is called Local trail file.

Trail Files:

Local Trail File: Files created at the Source database.

Remote Trail File: Files created at the Remote database.

DataPump:

The data pup reads the trail file in the Source database and sends the data over the network to the  remote trail file in the Target database. 

 Collector Process:

Manager process in the target database starts the background process called as Collector process.

Collector receives the data across the network and writes in to the remote trail file.

Replicat  Process:

It reads the data from the remote trail file and applies them to the target database.